The M4 has a great price per gigabyte and is also a great reader. Write performance, however, is mediocre at best.

The 512GB Crucial M4 is one of the highest-capacity solid-state drives we've tested; it also proved to be one of the faster readers. Using a Marvell 9174 controller, 25nm MLC (multi-level cell) NAND flash memory, and the latest SATA 6Gbps interface, the M4 read our 10GB collection of small files and folders at 416.7 megabytes per second (MBps). The drive was also quick when reading a single large file--it accessed our 10GB test file at 472.8 MBps.

The M4 proved to be much slower at writing files, however; it wrote our 10GB file/folder combo at a poky 265.1 MBps, and it wrote our single 10GB file at a leisurely 326.8 MBps. Because SSDs have a limited write lifetime, most people will tend to use an SSD to store the computer's operating system and application software than to store rapidly changing data (documents, photos, music, and other types of files). So it could be argued that the M4's excellent read performance renders this SSD a strong value all on its own.

This is a large capacity drive, however, and while flash memory has dropped in price considerably over the past year, it'll still cost you. Crucial lists the M4 at $425 for a bare drive. (A package that includes a mounting bracket and a SATA cable adds $5 to the price tag, while a kit with adata-transfer software adds $12, so make sure you know which one you're buying.) We found the kit that includes the data-transfer software (but no SATA cable) selling online for $400 (as of January 22, 2013). That's a chunk of change, but when you break it down to cost per gigabyte, you end up with a very reasonable--for an SSD, anyway--78 cents per gigabyte. A smaller-capacity high-performance drive, such as the 256GB Samsung 840 Pro (with a $239 street price), costs closer to 94 cents per gigabyte. Samsung's 512GB 840 Pro, meanwhile, fetches a street price closer to $490.

So the M4 scores big wins in two categories--price and read speed. Knowing that an SSD will inevitably wear out, however, buyers should also take the manufacturer's warranty into account. Corsair offers a three-year warranty where some other manufacturers--including Samsung--provide five years of coverage.A Overall, Crucial's 512GB M4 is a good deal..

Note : If you'd like to read more about SSDs in general, click here for our in-depth buyers' guide, where you'll also learn about how we test this type of storage device.

This story, "Crucial M4 (512GB): A fast-reading, slow-writing, high-capacity SSD" was originally published by
PCWorld.